Building unit, unit building and method of constructing the same

ABSTRACT

The present invention provides a building unit 12, wherein floor beams 22 which are structural framing members are connected to the lower end portions of columns 21 which are structural framing members, and ceiling panel 23 which is not a structural framing member is connected to the upper end portions of the columns 21.

FIELD OF THE INVENTION

The present invention relates to a building unit, a unit building and aconstruction method thereof.

BACKGROUND OF THE INVENTION

As a building unit which constitutes a unit building, there haveconventionally been box-shaped framing structure having four columns,four floor beams and four ceiling beams as structural framing members(structural members forming the framing sharing horizontal and verticalforces)(Prior art A).

Another conventional building unit is proposed in Japanese PatentApplication Laid-Open (JP-A) No. 57-201441, which has columns set onfloor structure with no ceiling (Prior art B).

However, these conventional arts have problems as described below.

(Prior art A)

Ceiling height RH cannot be secured large. That is, as shown in FIG. 9,the transportation height limit Hx for transporting the factorymanufactured building units to construction sites is fixed (3800 mmaccording to the present traffic regulations). Having the height oftruck loading floor at the technically lowest limit, the maximum valuefor the unit height UH is 2940 mm, for example. When span L is desiredto be about 6.3 m for the building unit of a two story house, therational depth dimensions B₁ and B₂ for floor beams and ceiling beamswhich are constructed with steel members of limited thickness areapproximately 240 mm. Taking the dimension above beam b₁ and thedimension below beam b₂ at 30 mm and 60 mm, respectively, the ceilingheight RH is UH-(B₁ +b₁ +B₂ +b₂)=2370 mm as the limit.

(Prior art B)

(1) Since a building unit is not provided with ceiling beams, ceilingcannot be provided at the factory manufacturing stage, and buildinginterior structure such as partitions cannot be completed. Therefore,the factory manufacturing efficiency cannot be improved (FIG. 8(A)).

(2) When a building unit is stored at store yard, the cover sheet whichis provided around the building unit droops down due to the rain waterdeposited on top thereof (FIG. 8(B)).

(3) When a building unit is hoisted up for such as installation, thereis a risk that the whole shape can be deformed (FIG. 8(C)).

In order to avoid the problem described in above (2), it is necessary totemporarily provide support members in-between the upper end portions ofcolumns of the building units, as disclosed in Japanese PatentApplication Publication (JP-B) No. 3-30659.

DISCLOSURE OF THE INVENTION

An object of the present invention is to secure ceiling height as muchas possible, while enabling the installation of ceiling portion into abuilding unit at the factory manufacturing stage.

The present invention provides a building unit which is a framingstructure comprising a plurality of structural framing members connectedto each other, wherein floor beams which are structural members areconnected to the lower end portions of the columns which are structuralframing members, and ceiling support members which are not structuralframing members are connected to the upper end portions of the columns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic drawing of an individual building unit of theinvention;

FIG. 1B is a schematic drawing of two individual building units abovethe floor beams of the building unit structure;

FIG. 1C is a schematic drawing of the FIG. 1B components assembled intoa unit building of the present invention;

FIG. 2 is a schematic drawing showing a unit building according to thefirst embodiment of the present invention.

FIG. 3 is a schematic drawing showing ceiling support members.

FIG. 4 is a schematic drawing showing the attachment of the ceilingsupport members.

FIG. 5A is a schematic drawing showing the horizontal ceiling membersconnected to the floor beams of an upper unit;

FIG. 5B shows in detail the connecting parts for connecting thecomponents of FIG. 5A;

FIG. 5C is a schematic drawing emphasizing the adjustability of theceiling heights between the floor beam and the ceiling panel;

FIG. 6 is a schematic drawing showing the connection system of a lowerstory building unit and an upper story building unit.

FIG. 7 is a schematic drawing showing the crucial details of FIG. 6.

FIG. 8A is a schematic drawing emphasizing unit building construction atthe factory;

FIG. 8B is a schematic representing a drooping problem not found withthe present invention;

FIG. 8C is a schematic representing a deformation problem not found withthe present invention;

FIG. 9 is a schematic drawing showing the transportation of a buildingunit.

FIG. 10A is a first fixing stage of the fixing process of the columns ofa building unit by manipulating a tool upon factory installed anchoringbolts;

FIG. 10B is a second stage of the fixing process;

FIG. 10C is a third stage of the fixing process;

FIG. 10D shows the final stage with the column fixed in place.

BEST PRACTICAL MODES OF THE INVENTION

Unit building 10 is assembled, as shown in FIG. 1, by setting lowerstory building unit 12 on top of footing 11, setting upper storybuilding unit 13 on top of the lower story building unit 12, and settingroof structure 14 on top of the upper story building unit 13.

(Lower Story Building Unit 12) (FIGS. 1-4)

The lower story building unit 12 is a frame structure, as shown in FIGS.1 and 2, which comprises four square-shaped steel pipe columns 21, fourrolled steel floor beams 22 and ceiling panel 23 (ceiling supportmembers) connected to each other in box shape.

The columns 21 and the floor beams 22 are structural framing memberswhich form the framework of the building unit 12 sharing the horizontaland vertical forces. The ceiling panel 23 is not a framing member. Thatis, the building unit 12 is assembled by rigidly connecting the floorbeams 22 respectively by welding or the like to the lower end portionsof the columns 21, and pin-connecting the ceiling panel 23 to the upperend portions of columns 21 respectively by fixing pieces 23C describedlater.

At this time, the ceiling panel 23, as shown in FIGS. 3 and 4, isconsisted of horizontal members 23A and vertical members 23B, and isattached to the upper endplates 21A of the columns 21 by rivets or thelike via fixing pieces 23C (fixing parts) connected to the horizontalmembers 23A. Ceiling sub-base 23D is attached to the underside of theceiling panel 23.

(Upper story building unit 13) (FIGS. 1 and 2)

The upper story building unit 13 is substantially the same as the lowerstory building unit 12, and is a frame structure, as shown in FIG. 2,which comprises four square-shaped steel pipe columns 31, four rolledsteel floor beams 32 and ceiling panel 33 (ceiling support members)connected to each other in box shape.

The columns 31 and the floor beams 32 are structural framing memberswhich form the framework of the building unit 13 sharing the horizontaland vertical forces. The ceiling panel 33 is not a framing member. Thatis, the building unit 13 is assembled by rigidly connecting the floorbeams 32 respectively by welding or the like to the lower end portionsof the columns 31, and pin-connecting the ceiling panel 33 to the upperend portions of columns 31 respectively by fixing pieces (not shown).

At this time, the ceiling panel 33, similarly to the ceiling panel 23,is consisted of horizontal members 33A and vertical members 33B, and isattached to the upper endplates 31A of the columns 31 by rivets or thelike via fixing pieces (not shown) connected to the horizontal member33A. Ceiling sub-base 33D is attached to the underside of the ceilingpanel 33 and scaffolding 33E is attached to the upper side of theceiling panel 33.

A unit building 10 is assembled by the following steps (1) to (5):

(1) Rolled steel footing beams 41 are laid on the ground. The footingbeams 41 are fixed to footings 42 made of precast concrete orpoured-in-place concrete by use of anchoring bolts and the like (FIG.1).

(2) The lower endplates 21B of the columns 21 of the lower storybuilding unit 12 are rigidly connected to the footing beams 41 by hightension bolts 43 and nuts 44 (FIGS. 1 and 2).

(3) The upper story building unit 13 is set on top of the lower storybuilding unit 12 (FIG. 6), and the lower endplates 31B of the column 31of the upper story building unit 13 are rigidly connected to the upperendplates 21A of the columns 21 of the lower story building unit 12 byhigh tension bolts 45 and nuts 46 (FIGS. 6 and 7).

(4) Reinforcing beams 47 (or roof structure 14) are set on top of thecolumns 31 of the upper story building unit 13, and the reinforcingbeams 47 (or roof structure 14) are rigidly connected to the upperendplates 31A of the columns 31 of the upper story building unit 13 byhigh tension bolts and the like (FIG. 6).

(5) At this time, the horizontal members 23A of the ceiling panel 23 ofthe lower story building unit 12 (horizontal members 33A of the ceilingpanel 33 of the upper story building unit 13) are disposed along thefloor beams 32 (reinforcing beams 47 or roof structure 14) of the upperstory building unit 13, and the horizontal members 23A are connected tothe floor beams 32 of the upper story building unit 13 by the connectingparts 48 at a plurality of positions in a longitudinal direction thereof(FIG. 5). The connecting parts 48 are fixed to the floor beams 32 withfixing screws 49A as well as fixed to the horizontal members 23A of theceiling panel 23 with the fixing screws 49B. In the unit building 10, byadjusting the fixing positions of the ceiling panel 23 to the connectingparts 48, the ceiling panels 23 of the neighboring building units 12 andthe ceiling heights thereof can be adjusted. In addition, the ceilingpanel 23 is supported by temporary supports or the like provided withinthe lower story building unit 12 until being connected to the floorbeams 32 of the upper story building unit 13 by the connecting parts 48.

Effects of the present embodiments will be explained hereinafter.

(1) The ceiling portion of the building unit 12 is constructed with theceiling panel 23 which is not a structural framing member, so that theceiling portion has no framing member. Since the ceiling panel 23 is nota structural framing member, the depth dimension B₂ thereof can be madesmall, and as a result, the ceiling height RH can be secured large.Moreover, under the condition that the unit height UH of the buildingunit 12 is kept within a certain range, depth dimension B₁ of the floorbeam 32 can be made large while keeping the ceiling height RH large,thereby considerably improving the floor beam strength. The floor beamstrength is directly proportional to the cube of the depth dimension B₁of the floor beam.

(2) Since the ceiling panel 23 is provided for the ceiling portion ofthe building unit 12, the ceiling portion can be assembled at thefactory manufacturing stage and the building interior structure such aspartitions can be completed, with the result that high efficiency offactory manufacturing can be attained. Moreover, the ceiling panel 23supports the cover sheet when the building unit 12 is stored so that thedrooping problem can be avoided. Furthermore, even if the building unit12 is hoisted up for installation and the like, the deformation of thetotal shape of the building can be prevented.

(3) The ceiling support members comprise the ceiling panel 23, and thehorizontal members 23A of the ceiling panel 23 are connected to thecolumns 21 via the fixing pieces 23C. Thus, the ceiling portion of thebuilding unit 12 can be simplified with regard to the assembly structureand assembly work.

(4) By connecting the structural framing members (columns 31 or floorbeams 32) of the upper story building unit 13 to the upper end portionsof columns 21 of the building unit 12 which comprises columns 21 andfloor beams 22 as structural framing members, rigid steel framingstructure can be constructed with the building units having no ceilingbeams (structural framing members). In addition, under the conditionthat the unit height UH of the building unit 12 is kept within a certainrange, depth dimension B₁ of the floor beam 32 can be made large, whilesecuring the ceiling height RH large, thereby considerably improving thefloor beam strength. For example, considering the depth dimension B₁ ofthe floor beam to be equal to the sum (2a) of the conventional depthdimension (a) of the floor beam of the upper story building unit and thedepth dimension (a) of the ceiling beam of the lower story buildingunit, the floor beam strength of depth dimension B₁ =2a is 8a³, that isfour times the strength 2a³ on the occasion that the floor beam and theceiling beam of the conventional depth dimension (a) are piled up.

(5) The horizontal members of the ceiling panel 23 are disposed alongthe floor beams 32 of the upper story building unit 13, and thehorizontal members 23A are connected to the floor beams 32 of the upperstory building unit 13 by the connecting parts 48 at a plurality ofpositions in a longitudinal direction thereof, so that even if the depthdimension h of the horizontal member 23A is made small, the deflectionof the horizontal member 23A can be minimized. That is, the panelthickness of the ceiling panel 23 can be made thin, and as a result, thelarge ceiling height can be achieved.

(6) By connecting the lower end portions of the columns 21 or the floorbeams 22 of the building unit 12 which comprises columns 21 and floorbeams 22 as structural framing members to the footing beams 41, andconnecting the structural framing members (columns 31 or floor beams 32)of the upper story building unit 13 to the upper end portions of thecolumns 21 of the building unit 12, rigid steel framing structure can beconstructed with the building units 12 having no ceiling beams(structural framing members). In addition, the floor beams 22(structural framing members) of the building unit 12 can be reinforcedby footing beams 41 with result that the depth dimension of the floorbeam 22 can be made small compared with the standard one and the largeceiling height can be achieved.

Now, modification of the present embodiment is explained, wherein thelower endplates 31B of the columns 31 of the upper story building unit13 are rigidly connected by bolts to the upper endplates 21A of thecolumns 21 of the lower story building unit 12.

Specifically, fixing process of columns 21 and 31 by bolts 61 usingfixing tool 50 will be explained (FIG. 10).

(1) Female screw portions 62 are provided at the upper endplate 21A ofthe columns 21 in the lower story building unit 12 fixed on the footingbeams 41.

(2) Bolt 61 is preliminarily set at the factory manufacturing stage tothe female screw portion 62 provided at the upper endplate 31A of thecolumn 31 in the upper story building unit 13. At this time, the upperend portion of the bolt 61 is mounted on the upper endplate 31A so as toprotrude from the upper endplate 31A of the column 31 (FIG. 10(A)).

(3) The sleeve 51 of the tightening tool 50 is engaged with the toolgripping portion 61E of the bolt 61 described in above (2). Before thissleeve 51 reaches the tool gripping portion 61E, the end-tip portion 54of the tightening tool 50 is inserted around the bolt 61, wideningelastically around the bolt 61, reaches or passes through the weakestengaging portion 61F closer to bolt main body 61A from the tool grippingportion 61E, and holds the tool gripping portion 61E tightly.

(4) By rotating the sleeve 51 with the handle of the tightening tool 50,sub-male screw portion 61D of the bolt 61 is screwed off from the femalescrew portion 62 of the upper endplate 31A of the upper story buildingunit 13, and then the bolt 61 which is held engaged with the end-tipportion 54 is inserted into the column 31 (FIG. 10(B)).

(5) Using the tightening tool 50, main male screw portion 61C of thebolt 61 which has been inserted into the column 31 is screwed onto thefemale screw portion 62 of the upper endplate 21A of the lower storybuilding unit 12 through the bolt insert hole of the lower endplate 31Bof the upper story building unit 13, and the column 31 (lower endplate31B) of the upper story building unit 13 is fixed to the column 21(upper endplate 21A) of the lower story building unit 12 (FIG. 10(C)).

During the screwing process of the tightening tool 50 of the above (5),the weakest engaging portion 61F of the bolt 61 breaks when apredetermined torque is attained (FIG. 10(D)). Thus, the bolt 61 isscrewed onto the female screw portion 62 with a predetermined torque.

(6) The tightening tool 50 is pulled out of the column 31. At this time,the end-tip portion 54 of the tightening tool 50 can be taken out of thecolumn 31 by engaging with the weakest engaging portion 61F of the bolt61 and tightly holding the tool gripping portion 61E which has been cutoff from the bolt main body 61A due to breaking of the bolt 61. By theabove (5), once the screwing of the bolt 61 onto the female screwportion 62 is started, unless the weakest engaging portion 61F of thebolt 61 is broken by screwing using the tightening tool 50, the end-tipportion 54 of the tightening tool 50 is held engaged with the toolgripping portion 61E which is integrated with the bolt main body 61A andcannot be taken out from the column 31.

The tightening tool 50 is prepared for the next use by removing by handor the like the tool gripping portion 61E which is tightly held by theend-tip portion 54 after the bolt breaking described above (6).

In addition, connecting method of the building units by use of thetightening tool 50 and the bolts 61 according to this modification maybe applied to the case where the lower endplates 21B of the columns 21of the lower story building unit 12 are rigidly connected to the footingbeams 41 by bolts.

Effects of this modification will be explained hereinafter.

(1) Bolt 61 is preliminarily mounted on the female screw portion 62 ofthe upper endplate 31A of the building unit 13 in a protruding state andplugs up the female screw portion 62 of the upper endplate 31A.Therefore, as long as the bolt 61 is mounted on the upper endplate 31A,the upper story building unit or the roof structure members cannot beassembled on the building unit 13, so that the construction cannot beproceeded. That is, when the upper story building unit or the roofstructure members are assembled on top of the building unit 13, checkingare always done for the fixing of the columns 31 of the building unit 13to the lower story building unit 12.

(2) Bolt 61 which has been inserted into the column 31 is screwed ontothe female screw portion 62 provided at the lower story building unit12. Therefore, comparing to the case where the bolt is provided at thelower building unit 12 onto which the nut inserted into the column 31 isscrewed, parts to be used become compact. That is, concerning the screwtype receptor provided at the lower story building unit 12, the screwtype receptor according to the present invention can be constituted byonly providing the female screw portion 62 at the upper endplate 21A ofthe column 21, and thus, is more compact than the one comprising thebolt at the female screw portion 62 provided at the upper endplate 21A.Moreover, concerning the screw type tightening part to be inserted intothe column 31, the screw type tightening part according to the presentinvention can be constituted by the compact bolt 61 having small volume(small diameter, short height) head 61B on top of the male screw portion61C, and is more compact compared to the one comprising large volume(large diameter, tall height) nut.

(3) In the process where the bolt 61 is screwed onto the female screwportion 62 of the lower story building unit 12, when the tightening tool50 reaches a predetermined torque, the weakest engaging portion 61F ofthe bolt 61 breaks. Thus, even though the tightening tool 50 is handledfrom outside of the column, the bolt 61 can be screwed with the desiredtorque, and the column 31 of the building unit 13 can be securely fixedto the lower story building unit 12.

(4) The tightening tool 50 can be attached around the bolt 61 only inone direction from the tool gripping portion 61E toward the bolt mainbody 61A, and engages with the weakest engaging portion 61F providedcloser to the bolt main body 61A, tightly gripping the tool grippingportion 61E. Therefore, once the tightening tool 50 is attached to thebolt 61, there is no chance for the gripping portion 61E of the bolt 61to drop off the tightening tool 50, thereby ensuring that the tighteningtool 50 inserts the bolt 61 into the column 31 and screw the bolt 61onto the female screw portion 62 of the lower story building unit 12.

(5) After the weakest engaging portion 61F of the bolt 61 breaks with apredetermined torque by the screwing operation of the tightening tool50, the tightening tool 50 is taken out of the column 31 holding onlythe tool gripping portion 61E separated from the bolt main body 61A ofthe bolt 61. Therefore, the tightening tool 50 cannot be pulled outuntil the bolt 61 is completely tightened up with a predeterminedtorque. Thus, the completion of tightening the bolt 61 with apredetermined torque can be easily confirmed outside the column 31 byvisually checking that the tightening tool 50 which has been taken outholds only the tool gripping portion 61E and not the bolt main body 61A.

Although the embodiments of the present invention has been explained indetails in the above, embodiments of the present invention are notlimited thereto. Accordingly, all changes which come within the range ofthe meaning of the present invention are intended to be embracedtherein. For example, the building unit according to the presentinvention may be directly connected to the footing without havingfooting beams therebetween. Furthermore, the upper story building unitconnected to the upper end portions of the columns of the building unitis not limited to the building unit without ceiling beams, and may be abuilding unit with ceiling beams.

INDUSTRIAL USABILITY

According to the present invention, as described above, large dimensionfor ceiling height can be attained while making it possible to assembleceiling to a building unit at the factory manufacturing stage.

What is claimed is:
 1. A building unit which is a framing structure,comprising:a generally rectangularly configured structure comprised ofsteel footing beams for fixating to concrete footings; a plurality ofassembled structural framing members for carrying all load bearingforces experienced by said building unit, said standard framing memberscomprising a plurality of open columns and an equal plurality of floorbeams connected to the columns, said columns each having respectiveupper and lower ends, upper and lower end portions delineating saidends, and corresponding upper and lower endplates attached to said endportions, each of said endplates closings said upper and lower endportions and having a centralized hole therein, wherein the floor beamsare connected to at least one of said steel footing beams and saidcolumns, wherein the floor beams connect with said columns at saidendplates and said floor beams connect with said columns at a respectivelower ends thereof; and ceiling members which are non-structural framingmembers, said ceiling members for supporting ceiling panels thereon,said ceiling members fixed to said columns near said upper ends thereof,said ceiling members hanging from each of said columns such that theload bearing forces which are transferred through said structuralframing members are not transferred into said ceiling members.
 2. Thebuilding unit according to claim 1, wherein said ceiling memberscomprise horizontal members connected to said column.
 3. A unit buildingusing the building units of claim 1 comprising:at least one lowerbuilding unit comprising a plurality of columns and an equal pluralityof floor beams, said floor beams connected to columns, said columns ofsaid building unit each having respective upper and lower end portions,wherein the floor beams are connected to the respective lower endportions of the columns and ceiling support members which are notstructural framing members, wherein a second plurality of said samestructural framing members are constructed into an upper building unit,which said upper building unit is connected to the upper end portions ofcolumns of the lower building unit with said means for connecting, andwherein said ceiling support members are connected to a column by use offixing parts.
 4. The unit building according to claim 3, wherein thehorizontal members of said ceiling panel are disposed along the floorbeams of the upper story building unit, and said horizontal members areconnected to the floor beams of the upper story building unit at aplurality of positions in a longitudinal direction thereof.
 5. A methodof constructing a unit building, comprising the steps of:providing andsetting a plurality of footing beams on the ground; assembling a lowerbuilding unit which is comprised of structural framing members, saidframing members comprising a plurality of open columns and an equalplurality of floor beams connected to said columns, wherein ceilingmembers which are non-structural framing members are fixed to saidcolumns near said upper ends thereof, said ceiling members hanging fromsaid columns such that load bearing forces experienced by said buildingunit are not transferred therein, said floor beams connected to therespective lower ends of the columns, said columns each havingrespective upper and lower ends, upper and lower end portions delimitingsaid ends and corresponding endplates attached to the upper and lowerend portions, each of said endplates closing said upper and lower endportions and having an identical centralized connecting hole therein;connecting the endplates of each of the lower end portions of saidcolumns to said footing beams thereby forming a lower building unit;assembling an upper building unit which is comprised of anotherplurality of structural framing members, said other framing memberscomprising a plurality of columns and an equal plurality of floor beamsconnected to said columns at the lower ends of said columns, saidcolumns each having respective upper and lower ends, upper and lower endportions delineating said ends and endplates attached and closing theupper and lower end portions of each column, said end plates each havinga centralized connecting hole therein; and connecting the structuralframing members of the upper building unit to the upper end portions ofcolumns of the lower building unit.
 6. The building unit of claim 1,further including means for connecting said column bottom endplates tosaid footing beams, said means comprising a female screw portioninserted into and secured within each said hole of said endplates and arespective anchoring bolt threadingly engaged within each said femalescrew portion, said anchoring bolt having a threaded male screw portionand a sub-male screw portion, said sub-male screw portion in threadingengagement within said female screw portion, wherein said anchoringbolts are pre-assembled within said open column prior to connection ofsaid framing members, and wherein said anchoring bolt includes a meansfor connecting said columns to said footing beams to a predeterminedtorque.
 7. A method of constructing a unit building, comprising thesteps of:providing and setting a plurality of footing beams on theground; assembling a lower building unit which is comprised ofstructural framing members, said framing members comprising a pluralityof open columns and an equal plurality of floor beams connected to saidcolumns, wherein ceiling members which are non-structural framingmembers are fixed to said columns near said upper ends thereof, saidceiling members hanging from said columns such that load bearing forcesexperienced by said building unit are not transferred therein, saidfloor beams connected to the respective lower ends of the columns, saidcolumns each having respective upper and lower ends, upper and lower endportions delimiting said ends and corresponding endplates attached tothe upper and lower end portions, each of said endplates closing saidupper and lower end portions and having an identical centralizedconnecting hole therein; connecting the endplates of each of the lowerend portions of said columns to said footing beams thereby forming alower building unit; assembling an upper building unit which iscomprised of another plurality of structural framing members, said otherframing members comprising a plurality of columns and an equal pluralityof floor beams connected to said columns at the lower ends of saidcolumns, said columns each having respective upper and lower ends, upperand lower end portions delineating said ends and endplates attached andclosing the upper and lower end portions of each column, said end plateseach having a centralized connecting hole therein; connecting thestructural framing members of the upper building unit to the upper endportions of columns of the lower building unit; inserting female screwportions into each of said connecting holes of said upper endplates onsaid columns of said upper and lower building units; pre-insertingcolumn connecting bolts into each of said female screw portions of saidupper building unit; aligning said connecting holes of the lowerportions of said columns of said upper building unit with said femalescrew portions of the upper portions of said columns of said lowerbuilding unit; inserting said connecting bolts into the female screwportions of the lower building unit columns by using a tightening tool,wherein said tightening tool screws said connecting bolts from saidfemale screw portions of said upper building units through saidconnecting holes of said lower portion endplates on said upper buildingunit columns, into said female screw portions of the lower buildingunit, thereby rigidly fixing the columns of the upper building unit tothe columns of the lower building unit.